A. FIELD OF THE INVENTION
This invention relates to electrical connector subassemblies and in particular to integrated terminal block-housing-circuit board apparatus.
B. PRIOR ART
It has long been the practice in electrical and electro-mechanical fields where there are housings or chassis for electrical equipment, to mount terminal blocks made of insulating material to desired portions of the housings. Wires are than attached to the terminals on the block. These terminal blocks are generally made of some plastic and have a plurality of screw or other types of terminals. For example, the terminals of one type each comprise metallic members or pieces having a generally U-shaped configuration. The horizontal bight portion has a threaded aperture for the screw connector. One leg penetrates a vertical hole and is adapted to be connected by soldering or other means to a selected point in an associated circuit board. It also includes another leg portion intended to anchor the metal member to the block by being inserted with a force fit into a slit in the block. Another type is substantially L-shaped having one vertical leg that passes through a slit in the block for attachment to any point on a circuit board. The other leg is horizontal and has two apertures. One of them is threaded to engage the screw around which a wire is wound or some other connector such as a spade connector is slid under before tightening the screw. The second hole is unthreaded and a pin is driven through it into the blocks to retain the metallic member in its proper cell between upright insulating barriers formed in the block.
Still other forms of terminal blocks exist but they all require separate attachment to the housing or other part of the apparatus and their manufacture requires relatively complicated assembly techniques as well as individual soldering attachments from each screw-terminal post to a lead in the associated circuit or circuit board.
There also exist binding post terminals for association with the edges of printed circuit boards. These consist of individual metal pieces which have a generally U-shaped clip-like construction. Each has a screw which is passed transversely through aligned threaded holes in each leg portion. The leg portions make ohmic contact with conductive portions formed either on the top or undersurface of the board as the case may be. Each must be assembled by slipping it over an edge of a printed circuit board which has at least one aperture that can be aligned with a corresponding threaded screw hole in the metal clip itself. Ordinarily there is no associated anti-leakage insulating barrier between closely adjacent ones of these individual binding posts.
The prior art U.S. Pat. No. 4,247,882 to Prager shows terminal blocks and associated boards or plates having tab ends separated by slots, with contacts as well as screw terminals, but there is no showing of integral construction of the tab ends or the screw terminals with the printed circuit board itself. Knohl U.S. Pat. No. 2,762,026 shows a plug of ceramic rubber insulating material having a plurality of sheet metal prongs that are attached to terminals in recesses by means of screws. However, the plug has no printed circuit on it and there are no barrier walls separating adjacent terminals from one another. Maltby U.S. Pat. No. 3,090,936 shows electrical connectors having U-shaped members which engage terminals in a terminal block. It also shows an intermediate portion and wire connections as well as slots which engage vertical walls. However, there is no printed circuit involved and the U-shaped members are not coplanar or formed integrally with a circuit board. Callan U.S. Pat. No. 3,729,857 shows a printed circuit card having several slits and a strip which is an electrical connector mounted on its edge. The strip has sockets for receiving pins on a terminal board which are, in turn, connected to screw terminals separated by perpendicular insulating barriers. The edge portions of the board which are separated by slots are not equipped with holes or meant to receive screws as in the present invention.
It is therefore among the objects of the present invention to provide:
1. An integral housing-terminal board-circuit board assembly that cuts down on many separate assembly operations.
2. A cheaper substitute for the assemblage of separate terminal blocks, circuit boards, and housings on which the blocks are mounted.
3. A circuit board which has integrally formed apertured tabs to which wires may be directly attached by screws which simultaneously anchor the wired tabs to the housing itself.